Various types of skis, of which numerous variants exist, are already known. These skis are constituted by an elongated beam whose front end curves upward so as to form a tip, and whose rear end is also curved, although in less pronounced fashion, so as to form the heel-piece.
Present-day skis normally have a composite structure in which different materials are combined, so that each of them comes optimally into play, given the distribution of the mechanical stresses generated during ski use. Accordingly, the structure generally comprises peripheral protective elements, interior resistance elements which resist flectional and torsional stresses, and a core. These elements are assembled by adhesive bonding or injection, the assembly generally being produced under heat in a mold having more or less the final shape of the ski. Next, the lower surface of the ski is ground down or sanded so as to make it level, and its surface quality must be faultless so as to impart to the ski its sliding and maneuverability properties. This operation is conventionally performed by passing the lower surface of the ski on an abrasive wheel turning at high speed, longitudinal travel of the ski on an abrasive wheel being provided for by a drive wheel supported on the upper surface of the ski. The smallest modification in the longitudinal travel of the ski causes a change in the abrasion operation performed on the sole, which consequently exhibits defects. While the continuity of the travel imparted to a conventional ski whose upper surface has no breaks poses no special problems, the same is not true for skis comprising a projecting platform, for example in the area in which the bindings are mounted. In this case, at the moment when the drive wheel rises suddenly on the platform, there is a break in the continuity of travel, the process of abrading the sole is disrupted, and the sole of the ski then exhibits defects of levelness and surface quality.